Bone marrow and histochemical features of malignant histiocytosis

Objectives: To study the hematological and histochemical features of malignant histiocytosis cases diagnosed at King Khalid University Hospital. Materials and methods: This is a retrospective analysis of malignant histiocytosis cases diagnosed by bone marrow examinations at the Hematology Section, Department of Pathology, King Khalid University Hospital. The medical records were evaluated for clinical symptoms and signs at presentation and peripheral blood count. Bone marrow aspirates and biopsies were reviewed for morphological features. Immunohisto-chemical staining of bone marrow trephine biopsies was performed. Results: Over 11 years, from February 1984 to March 1995, four cases of malignant histiocytosis were diagnosed at King Khalid University Hospital (KKUH) in Riyadh. They were two males and two females. The age range was 25-56 years. The predominant symptoms at presentation were fever and fatigability. All patients had hepatomegaly and three had splenomegaly. One patient had localized lymphadenopathy and skin involvement. Three patients had pancytopenia while one patient had anemia, thrombocytopenia and leukocytosis. Immunohistochemical stains on three cases showed positivity with ∂1 antitrypsin and lysozyme. One case showed CDS (T cell marker) positivity by flow cytometry. The clinical, hematological and immunohistochemical staining findings are described.